Chain block



Sept. 20, 1932. J, 5 PARKER 1,878,312

CHAIN BLOCK Filed Feb. 26, 1.931

Patented Sept. 20, 1.932 l a Y I i UNITED STATES' P'AT-ENroFFios Joints. PARKER, or eLEvELANn, omo f CHAIN nnoox i y Appiicationmearebruary. ze, 19a1.,seria1No. 518,423. n I i ij-f tation and displacement l more particularly toa dierential type ofl bya Cotter pin 14 whichgextends kthrough chain block and has for its primary object aligned openings provided 1n an integral-exi. to provide a `chain blockof Amaterially intension -l'and the adjacent endofthe p1n 12. "5" creased efficiency at low manufacturing. oost. A .cylindrical bearing member 16 is disposedV 55" i :The efficiency of Vchainbloeks of the presaXlally of the pin 12 and is rotatably mounted: 1 ent'oonstruotion is very low and has but two 'on a pair of longitudinally yspaced`ant1`fric redeeming yfeatures, its Capability of'supporttion roller bearings 17 disposed "betweenfthe ing vitsb'load andthevcheapness of its manuinner surface of the cylindrical bearing mem- 2,. 16 facture. VInasmueh as the 'load is supported ber 16 andthe outer surface "of the pin '12.5'` 6o'` frictional resistance; thesame yfrictiona-l This bearing member 16 is normally'freetof.

' resistance must necessarily be overcome in rotate'in one direction but is preventedfrom raising the load to theidesired height with rotation in the opposite ldirection' andwhile the result, that agreatamount of energy and any suitable means `may be employed to aci- I labor is required, thus reducing the eilicienoy eomplish this result itis preferred'to provide' 65" ofthe' chain block. Y f a plurality vof `Clutch teeth 18 formed uponI It is afurther object ofthe present in-y the inner surface of the bearing `memberll ven -ionftoyprovide a construction' wherein between the inner'adjaoent ends ofthe rollert Y the loadmay be raised to the'desired height bearings 17 The pin 12 i l provided witha '2 without any" appreciable resistance and the transversely ext-ending borev 19 'withinwhich 70 load supportedby sulioient frictional rei is slidably mounted a detent or dog 20V`whi'ch'f sistanoe to preventits loweringby reason of is adaptedto normally engage the'internal` l Y its own weight. i teeth 18 4and which is heldin engagement;

With the objects above indicate-dand other therewith by a coil spring 21 disposed bei# This invention relates to chain blocks and is Secured against ro im; objectsher'einafter explained inview the in tween the innerend ofthe detent andit'he 775:

vention consists in the construction and combase `ofthe bore 19. lA. pin 22 extends transbination of elements hereinafter described `versely through an opening in the detenti`20 and claimed. Y and-has its ends extendingbeyond thedetent Referring to the drawing and adapted to engage .with al portionf23 30 `Figure 1 is an end elevational view of a formed upon the pin112 to preventabnormal 8-.02Y

5 Fig. 3 is a fragmentary transverse sec- 1n a clockwise directionY between thevv pin 12 3 chain-block partly in vertical section to more depression of the detent 20. v Viewing Fig. 3

clearly illustrate the invention. Y more particularly it will benoted that the in-`l Fig. 2 is a side velevational vievvof the ternal teeth 18 andthe detentf20 Cooperate a chain block shown :in Figure 1. inia manner which permits relative rotation tional view taken on line 3-3 of Fig. 1. andthe bearing member 16 but which p-re-l l Fig. 4 illustrates a hoisting apparatus of vents relative rotation therebetween inVv a wliich'the `hoist. block embodying the present counter-clockwisedirectionl During the -ro'-j y l invention isa part. f tation of the bearing member 16 in a clockv 40- Fig. 5 is a'fragmentary sectional viewsimwise direction itis to bernoted that the bear- 90' ilar to Fig. 2 but showing a modified construcing member isv anti-friotionally support'ed i tion embodying the present invention. upon the'pin l2 withthe result'that' praeti- `In the drawing the vohainblock embody-l cally allfrictional.resistanoeis eliminated. n ing the invention, comprisesav yoke 10`pr'efer- A double'sproeketwlieel 2t`is herein illus` 5T ably inthe form of a metal casting, which is trated. but it should beunderstood that-other 55.

open at its lower end and has swivelly contypes ofsprocket wheelslnay'befemployedjif nected at itsupper or opposite end 'a hoolrll. desired7 and `consists of a. p'airroiVA chain ree' y. pin or supporting member 12 is disposed ceiving grooves25 and 26 being in thefpresent Y within transversely alignedfopenings 13 proinstanceofdierent diameters. The sprocket 50 vided in the lower portion of the yoke 10 and wheel 2,4 isprovidedV axially withfahub 27'.` i90 I supported by Y pointedoutthat. the efficiency of the hoist-l sprocket lwheel: 24, is looped :subsequently passesaround the chain groove integral spokes 28. This hub 27 has an axially or longitudinally extending bore 29 of a diameter slightly greater than the Voutside diameter of the bearing member 16 which is normally disposed therein and functions as a bearing'for the sprocketwheel.`

ing portions 30 which enclose portions ofthe sprocket wheel 24 and prevent, accidental ldis#` engagement between the chain. and the sprocket wheel, v i

In Fig'. 4 there' is illustrated Ithe upperj chain block embodying thev a present inven tion and a lower chain block 31-l which is of the usual construction except that the sheave orsprocket wheel 32 ismounted for rotation onananti-frictionbearing'jr33. s While this'V mounting 'is lnot the sub' particular "type .of jeetmatter of the present invention it is to be ingapparatus isl materially increased when the sheave ofthe lower chainblo'ck is antifrictionally mounted. .An endless handl chai-n 34 isemployed for raising land lowering the load andat its'lowerend extends aboutthe lower sheave 32while its upper .end passes 26 of the upper down at '35 and around thereceiving groove ,Q5-of tliefuppersprocket wheel 24. `It will therefore be readi-l seenthat pulling upon the looped portion 35of thechain 34 inone direction wil-lraise'the `load supported upon ,the hookl 36 of the'lower chain block 31v while' pulling the chain lin theopposite ydirection wi-llalower the load. g A; Y Y

yIn the types (jf-differential chain blocks whichsare manufactured at present the load is frictional-lyY resisted and supported vinfany desired positionin such a'mannerrto prevent the load from lowering by reason of Y,its own weight. Therefore, it follows that in orderV to the-.desired height, suffi-y, cient energy and labor must be exercised to overcome this frictional resistance. It will therefore be readily understood that chain blocks offthis particular' `construction? are materially ineficient in lthis'respect. This invention hasovercome this objection by per-- to raise l the load mitting'theloadto be raised in an unresistedl e Gir lloa"dfthelooped portion manner by'virtue .of the roller bearings 17 e ,and subsequently prevents lowering of the load by reason of its-Own'weight through fric-v tional-V resistance between the sprocket ywheel 24 and the bearingmemberl. Y A

ln, operating the bearing block to raise' the 35 of the endless handchain 34 ispulled so as ,tionof the chain to rotate the sprocket wheel 24 in a. clockwise direction.l The internal teeth 18 on the bearing member 16 therewhich offers no unrestricted and reamount of energy due to 17. The frictional resistfore slide over the detent 2O resistance and rotation is quires a minimum the roller bearings ance between ,the sprocketk wheel 24 and the" bearing member 16 is s` lfici'ent to Acause these members to be rotated bearing member 16 is rotated in a clockwise -dire(:tioriv-"lVVhen-the load has been raised to the desired height the weight of the load itself tends to settle or lower, in which case the bearing: member 16 starts to rotate in a counterclockwise:direction This movement however lis prevented by engagement ofthe detent 2() withwtthe internal teeth-18 onthe e bearing member-16 and any loweringof the load is prevey a resistance betweenthe sprocket wheel 24 and the bearing 1.6;.` e TheTv raising .ofthe l.load iis also assisted by means of the roller bearings 33 upon Whi -h the :lower sheave 32is mounted thus eliminating any .,frict'onal resistance. at', this point. Y j y Y In Fig..5 I have shown a modied construc tion wherein any desired amount of frictional lresistance may be obtainedi Theboref29 of .the hubl 2 7 isprovided .with a circumferentially extendinggroove 36, adjacent .its center portimeand, of the desired width'so as vto provide adjacentfbearing'surfaces 37-and 38.1 2A 4 V similar to thebearingmember16 inFig. is

" provided land consists in separate but coop.d erating,A Y. members. 39- Aand( 4()l t engageable with the bearing portions 37 andi 38 respectively rlfhese members 39 and 40yare rotatably supported onanti-friction "roller bear.- ings 13 provided` in the, arms of the yokef10.. f y 'i The member 39 intherpresent instancejis in unison when the` circular bea-ring element 17 `:which in turn. arey supported upon-the pin L12 which ,"hase its ends mon-rotatably; mounted in the openings tedb. reason ofthe Vfrictional block .embodying the invenprovided with a plurality of internal teethA 18 normally engaged by the detentV 2O againsty the tension of 'the-spring' 21. The operation is precisely the same as the device Aillustrated inFig-2.

Y However if the frictional resistance'o'ccurs onlybetween the-surface 37 andthe member 39it will be apparentthat' by changing the contacting area of anyl desiredl amount may be'obtair'i'ed.- i 'f .Y

While I have described the-preferred em-A bodiments "of the invention'itf is tobe understood that l am not to be limited theretoinasi much as changes and mo'dications gmay be resorted to without departing-from the spirit ofthe invention as defined in -thefappendedclaims.V Ti* A- .-j

A Having vthus described 'myinvention I claim: 5

these engaging e surfaces opposite direction.

1. In a chain block, a rotatable chain member, a stationary supporting member about which said chain member rotates, and a member mounted for substantially unresisted rotation in one direction upon said supporting member, said member in turn frictionally resisting member in one direction.

2. In a chain block, a rotatable chain muem-V supporting member aboutber, a stationary which said chain member rotates, 'a member mounted for substantially unresisted rotation in one direction upon saidsupporting member and providing a. friction bearing for said chain member in its rotation relatively to taining said member against'rotation in the 3. In a chainblock, a supporting member Vcarried by said yoke, a member mounted for rotation in -one direction upon said supporting member, means for preventing rotation of said member in its opposite direction, and a frictionally restricted rotation in the rotation of said chain y said member, and means vfor main-v yoke, a stationary lone direction upon said bearing surface to provide frictional resistance to relative bers, and'means'for maintaining said members against rotationin the opposite direction.

In testimony whereof, I hereunto aiiix my signature.

` JOHN S. PARKER.

rotation between said mem-v sisted chain engaging member rotatably mounted on said member.

4:. In a chain block, a yoke, a stationary supporting member carried by tion in one direction upon said supporting member, means for preventin rotation of said member in the opposite irection, and a frictionally resisted chain engaging member rotatably mounted on said member.

5. In a chain block, a yoke, a stationary supporting member carried by said yoke, a member anti-frictionally mounted for rota tion upon said supporting member, interengaging means between sald supporting member andsaid member for maintainingsaid Y and engageable with saidspaced bearing surfaces to provideV frictional resistance to relative rotation betweensaid members, and means for maintaining said members against rotation in the opposite direction.

In a chain block, a rotatable chain member .having an axial bore comprising a bearing surface of less length than the length said yoke, a member anti-frictionallymounted for rota' spaced bearing surfaces, a`

of said bore, a `stationary supporting memy Y ber about which said chain member rotates, a member mounted Vfor substantially unre-l 

